On the first day of the trial which included opening statements and witness questioning, Crown prosecutor Joshua Phillipspresented the jury with the letter that Mr Peros wrote.

He read it to the jury; Mr Peros had written that Ms Blackburn had cheated on a previous partner about 10 times, including with a married man.

"You can never be trusted," Mr Peros wrote in the letter.

"We have had problems with sex for six months."

Shannah Blackburn, Shandee's sister arriving at court.Tony Martin

He wrote that Ms Blackburn had used sex in exchange for cheaper drugs, Mr Phillips said.

Mr Phillips also told the court about a threatening comment that Mr Peros had made about Ms Blackburn during an Australia Day party about two weeks before Ms Blackburn's death.

The prosecutor said Ms Blackburn had been "brutally murdered". She had been stabbed 23-25 times and in the process her larynx and voice box had been cut.

"There was no opportunity to call out," Mr Phillips said about her death on February 8, 2015.

"Neighbours came to her aid when they heard her gasping for air, but they couldn't save her."

The jury was also shown a picture of the area as well as CCTV footage taken from a private residence that shows Ms Blackburn walking home moments before a figure ran across the road in the direction she walked.

Mr Phillips told the court the person running across the road was Mr Peros.

But in his opening address defence barrister Craig Eberhardt argued that all evidence to suggest that Mr Peros committed the murder was circumstantial.

Paul Beardmore, Vicki Blackburns husband leaves court.Tony Martin

He said the letter by Mr Peros had been penned after a messy break up and "he simply explained why he did not want to continue the relationship".

"We can't impose our own moral values on other and their relationship," Mr Eberhardt said.

"There is not a shred of evidence that Mr Peros was directly involved."

He said the prosecution's case was "entirely circumstantial" and it had to be proven beyond a reasonable doubt that someone else didn't do it.

"This was a robbery to get money for drugs that went wrong," Mr Eberhardt told the court.

"The only eye witness said the pair were struggling for a handbag."

He said there would be CCTV footage shown during the course of the trial that would show a person walking away from the scene with a large white handbag.

A witness leaves court.Tony Martin

The Australia Day party

The first witnesses called Wednesday were those at the Australia Day party where it is alleged John Peros spoke about his former partner in an aggressive and threatening manner.

But the defence attempted to cast doubt on the recollection of those witnesses that night.

Crown prosecutor Joshua Phillips argued that Mr Peros was talking about former partners with Charlene Perry and Nicole Hutchinson when he said that he 'hated the c**t' referring specifically to Ms Blackburn.

The party was two weeks before Ms Blackburn's death, which came after she walked home from work at the Harrup Park Country Club.

Four of the people who were at the Australia Day party - Charlene Perry, Nicole Hutchinson, Melissa Oliver and Liam Aleman - appeared as witnesses before the Mackay Supreme Court Wednesday.

Ms Perry told the court three of them were sitting out the front of her home about 1.30am waiting for a taxi when Mr Peros had said that 'she (Ms Blackburn) would be better off dead'. The rest of the party was inside at the time.

Shandee Blackburn

But under cross-examination the defence questioned Ms Perry's recollection about the night.

The defence read out text messages from Ms Perry's phone to her nephew, Mr Aleman, which indicated in the months leading up to the party she was buying cocaine and ecstasy and regularly using the drugs.

Ms Perry admitted in court yesterday to taking drugs but said she had not taken drugs on Australia Day. She did say she was heavily intoxicated after drinking for most of the day at three pubs before continuing to drink when they went home about 9pm.

Under cross examination she said she "thought" Mr Peros had made the comments about Shandee, but was "'not 100% sure".

A second witness questioned yesterday, Nicole Hutchinson, told the court that Mr Peros had said 'I hate that c**t, I want to stab her'.

The defence presented Ms Hutchinson's initial police statement to the court, as well as a second statement that police had taken on April 6, 2013, where there had been no mention of the word 'stab'.

"Fourteen months after the event and 12 months after the previous statement is the first time there was a mention of stabbing," defence barrister Craig Eberhardt told the court.

Ms Hutchinson wasn't sure exactly what she heard "at the time" so left it out of initial statements, but said her latest statement was correct.

Mr Aleman, the last witness for the day, told the court he had been there when Mr Peros had been talking about former partners and heard the threats and the accused describing Ms Blackburn as a c**t.

He said he remembered it because he was shocked how angry Mr Peros sounded. He said it was out of character for Mr Peros.